Automatic circuit-opening switch eor ignition systems



G. A. REAIVI AUTOMATIC CIRCUIT OPENING SWITCH FOR IGNITION SYSTEMS.

APPLICATION FILED APR-18,1917.

Patented Apr. 6, 1920.

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"UNITED STATES PATENT OFFICE.

GORDON A. BEAM, or DETROIT, MICHIGAN.

AUTOMATIC CIRCUIT-OPENING SIVITCH FOR IGNITION SYSTEMS.

Application filed April 18, 1917.

To all whom it may concern:

Be it known that I, GoRDoN A. BEAM, a citizen of the United States of America, residin at Detroit, in the county of Wayne and tate of Michigan, have invented certain new and useful Improvements in Automatic Circuit-Opening Switches for Ignition Systems, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to automatic circuit-opening switches for ignition systems, being particularly designed for use in connection with the ignition systems for internal combustion engines, and it is the primary object of the invention to obtain a construction which will insure opening of the circuit when the engine is not: in use, but will nevertheless delay this opening so as not to interfere with normal operation. In other words, the construction is such that the stall ing of the engine or the delay required for starting the same will not cause the auto matic opening of the switch, but in case the ignition circuit is not manually opened when the engine is not in use the automatic mechanism will effect an opening after a brief delay. The invention therefore comprises the novel construction of circuitopening means and delaying means as hereinafter set forth.

In'the drawing:

Figure 1 is a diagram; and

Fig. 2 is a longitudinal section through the delaying or retarding means.

In the present state of the art, ignition systems for explosion engines usually in clude a primary circuit, a timer therein and an induction coil or transformer for increasing the voltage. Where the engine is in operation the successive opening and closing of the primary circuit by the timer will produce a pulsating electric current which will induce a high tension current in the secondary coil of the transformer. The reaction or inductance of this coil will in turn restrict the flow of current through the pri mary circuit so that under normal operating conditions the volume of current flowing through the primary circuit is less than where the engine is not in operation. The increased flow of current could be used di rectly for actuating a circuit-opening switch, but with such an arrangement the accidental stalling of the engine would instantaneously open the ignition circuit and it would be Specification of Letters Patent.

Patented Apr. 6, 1920.

Serial No. 162,830.

difficult to maintain the circuit closed dur' ing the starting operation. lVith my improvement the increased flow of current when the inductance is not in operation is used for the heating of a resistor coil, said coil being of a character to greatly increase its resistance upon increase in temperature. This increase in resistance is used for shunting the current through a magnetic device, which in turn opens the circuit. The timing of the opening of the circuit can be accurately controlled by properly proportioning the coil and also by the proximity of a heat-absorption body and heat insulation means.

As shown, A is the primary circuit, B is the battery, 0 is the timer, D is an induc tion coil and E is a manually-operable switch for closing the circuit. As specifically shown, this switch is a push-button, which when pressed inward closes connec tion between contact members F and F, a spring G serving to retract the button, and a latch I-I engaging a detent I operating to temporarily hold the switch in closed position. The automatic releasing device comprises an electro-magnet J, which when sufficiently energized will effect the disengagement of the latch H, permitting the spring G to retract the button E and thereby separating the contacts F and F. This electromagnet is in a branch K of the main circuit A, and in a parallel branch L there is arranged a resistor coil M.

With the construction as thus far described, when the button E is pressed inward to close the contacts F and F the primary electric circuit is established, the current flowing through the timer, coil and the branch circuits, including respectively the magnet J and the resistor M. In ordinary operation where the timer is periodically opened and closed, the inductance of the coil is sufficient to limit the flow of current through the primary circuit, so that the magnet J will not be sufliciently energized to release the latch or detent H. Also the volume of current passing through the branch L and resistor M is insufficient to materially raise the temperature of the latter. 'On the other hand, when the engine is stopped and the inductive resistance of the coil therefore ceases there will be an increase in flow of current through the primary circuit which. divides between the branches K and L. The portion flowing through the branch L and resistor M therein will cause the heating Of this resistor, the heat gradually accun'iulating until sullicient temperature is attained to materially increase the resistance of the resistor. This in turn will shunt current from the branch L through the b 'anch K, and the increase of how through the magnet J will energize the same sufiiciently to release the latch or detent H and permit the opening of the circuit.

To render the operation of. this automatic mechanism more certain, I have provided a construction of electro-magnetic releasing means in which there is provided means for producing a succession of impulses for reeasing the latch H. Thus if the first impulse fails succeeding operations will be effective. Specifically, this mechanism comprises a second magnet N, which together with the magnet J is preferably in the form oi: a solenoid having a common movable core 0. P is a horseshoe magnetic core which embraces the magnet or solenoid N, one arm P thereof passing between this magnet and the adjacent end of the magnet J. Q is an armature hinged to the arm 1 and extending to the opposite pole R of the magnet J. S is a spring for normally retracting the armature from the pole R. and T are contacts which are closed when the armature is attracted to said pole. The arrangement is such that when current is passing through the branch K and magnet J therein, the core 0 will be moved in the position where it connects the pole 'R- with the magnetic arm P and through the armature Q, will complete themagnetic circuit. Thus, if sufficient current is flowing through the magnet, as is the case when the heating of the coil M shunts current from the branch L, the armature Q will be attracted, closing the contacts T. This will establish a circuit through the magnet N, which circuit is not in series with the timer and coil, but has an independent ground U. Conse quently the lower resistance of this circuit will cause a flow of current therethrough, energizing the magnet N to a greater degree than the magnet J, whereupon the movable core 0 will be shifted to a position symmetrical with respect to the magnet N. This movement will cause the end of the core to impinge against the latch member lzl, tendingto withdraw the same from the shoulder I to release the button E. If, however, the blow is insufficient to release the latch, the circuit of the magnet N will be opened, this being caused by the withdrawal of'the core from between the pole-piece t and arm P, which causes a break in the magnetic circuit and permits the spring S to retract the armature Q. As soon as the circuit for the magnet N is broken and said magnet is deenergized, the core 0 will be again moved to its original position, whereupon the magnetic circuit of the magnet J is again established, the armature Q is attracted and the circuit for the magnet N closed. Consequently a series of impulses or movements of the core 0 will be caused, each time the core striking against the latch H until said catch will be released.

As has been stated, the timing of the operation of the automatic switch-opening device is effected by the resistance of the resistor-coil M, and also by the adjacent l eat-absorbing body and the heat insulation surroululing the same. As shown in Fig. 2, the coil M is wrapped about an insulated core member V which constitutes the heatabsorbing body and heat-insulation V surrounding the coil. The proportion of the parts is such that a definite time interval is required after the inductance of the coil D is cut out in which heat accumulating in the core V, and it is only when sufficient heat is accumulated to raise the temperature of the coil M to a predetermined point that the current will be shunted and the releasing mechanism operated, as above described.

lVhat I claim as my invention is:

1. The comlnnation with an electric circuit, of a circuitopening switch and a pulsating electro-magnetic motor for delivering a "accession of blows to actuate said circuit-opening switch, comprising a solenoid in said circuit, a second solenoid in alinement with said first solenoid and in a normally open circuit, a core movable through said solenoids from one to the other, pole-pieces on the first solenoid, magnetically connected by said core when bridging therebetween, an armature in operative relation to said pole-pieces and a switch operated by the movement of said armature to said pole-pieces and closing the circuit for the second solenoid, said second solenoid being of greater magnetic power than the first solenoid and thereby drawing the core member therefrom to break the magnetic circuit in the first solenoid and release the armature, whereby the circuit of the second solenoid is broken.

2. The combination with an electric circuit, of a circuit-opening switch and a pulsating electromagnetic motor for delivering a succession of blows to actuate said circuit-opening switch, coi'nprising two alined solenoids difi'ering in magnetic power, the weaker of which solenoids is permanently connected in said circuit, a core movable through said solenoids from one to the other. and means for making or breaking the circuit of the stronger solenoid according: as said core is positioned within the weaker or the stronger solenoid.

3. The combination with anelectric circuit, of a circuit-opening switch and a pulsating electro-magnetic motor for delivering a succession of blows to actuate said circuitopening switch, comprising a pair of alined solenoids differing in magnetic power, the weaker of said solenoids being permanently included in said circuit, a core movable through said solenoids from one to the other, and means utilizing the decreased resistance of the magnetic circuit of the weaker solenoid resulting from location of said core therewithin to close the electric circuit of the stronger solenoid to attract said core'to the latter.

4-. The combination with an electric circuit, of a latch member and a pulsating electro-magnetic motor for delivering a succession of blows to actuate said latch memher, said motor comprising two alined solenoids differing in magnetic power, the weaker of which solenoids is permanently connected in said circuit, a core movable through said solenoids from one to another, and means for making or breaking the circuit of the stronger solenoid according as said core is positioned within the weaker or stronger solenoid,

The combination with an electric circuit, of a latch member and a pulsating electro-magnet motor for delivering a succession of blows to actuate said latch member, said motor comprising a pair of alined solenoids differing in magnetic power, the weaker of said solenoids being permanently included in said circuit, a core movable in said solenoids from one to another, and means utilizing the decreased resistance of the magnetic circuit of the weaker solenoid resulting from the location of said core therewithin to close the circuit of the stronger solenoid to attract said core to the latter.

6. The combination with an electric circuit, of a latch member and a pulsating electro-magnet motor for delivering a succession of blows to actuate said latch memher, said motor comprising an impact member for actuating said latch member, two electro-magnet devices controlling said impact member and differing in magnetic power, the weaker device being permanently connected in said circuit and tending to withdraw said impact member from the latch member and the stronger device tending to shift the impact member into engagement with the latch member, and means for making or breaking the circuit of the stronger electro-magnet device according as the impact member is withdrawn from or engaged with the latch member.

7. The combination with an electric circuit, of a switch in said circuit, a latch member for maintaining said switch closed, a pulsating electro-magnetic motor insaid circuit for delivering a succession of blows to actuate said latch member.

In testimony whereof I affix my signature.

GORDON A. BEAM. 

